I have a 2002 chevy blazer 4x4 with 4hi , 4lo, and 2h.
had some transmission issues and just replaced the transmission. About 6 months later the pump practically Grenada’s. Replaced the pump. (Transmission shop) replaced it. Have had the vehicle back for 5 days and now out of nowhere the 4x4 is trying to engage. You can hear the gears in the front transfer case click (sounds terrible) I can jack the vehicle up when it’s off and the wheels
on the front don’t make the noise. But when vehicle is on it makes the noise turning the tires by hand.

I can see the actuator engaged under the battery and the passenger side makes a loud sound. I haven’t pulled the vacuum hose off yet to let it disengage. Looking for some advice. I did notice when I select 4lo the light flashes and I can select 4hi and 4lo continues to flash. I can switch it back to 2 Hi and the acuator stays engaged until the engine is shut off.